Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan.
Department of Ocular Pathophysiology, Yamaguchi University School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan.
Jpn J Ophthalmol. 2011 May;55(3):190-195. doi: 10.1007/s10384-011-0018-2. Epub 2011 May 15.
Orthokeratology for correction of myopia reduces corneal power by flattening corneal curvature and thinning central corneal thickness (CCT). Measurement of intraocular pressure (IOP) with a noncontact tonometer is known to be affected by CCT and corneal curvature. We investigated the influence of orthokeratology on such measurements of IOP.
This was a prospective, interventional case series derived from a clinical trial of orthokeratology lenses in two hospitals. Both eyes of 45 subjects were fitted with reverse-geometry lenses, worn for more than 4 h overnight for 52 weeks. Uncorrected visual acuity, refraction, IOP (with a noncontact tonometer), CCT, and corneal curvature were measured.
Uncorrected visual acuity, spherical equivalent value, IOP, CCT, and the radius of corneal curvature were 0.93 ± 0.27, -2.87 ± 1.05 D, 13.5 ± 2.5 mmHg, 536.2 ± 39.6 μm, and 7.88 ± 0.25 mm, respectively, before orthokeratology, and 0.17 ± 0.34, -1.05 ± 1.18 D, 12.4 ± 2.7 mmHg, 528.6 ± 40.8 μm, and 8.10 ± 0.31 mm at 52 weeks after treatment. The changes in all parameters were significant, and the change in IOP was significantly correlated with that in CCT at 24 weeks and thereafter.
Orthokeratology for myopia leads to a decrease in IOP measured with a noncontact tonometer, likely as a result of the associated decrease in CCT.
角膜塑形术通过使角膜曲率变平并使中央角膜变薄来矫正近视，从而降低角膜的屈光力。已知使用非接触眼压计测量眼压会受到角膜曲率和角膜厚度的影响。我们研究了角膜塑形术对这些眼压测量的影响。
这是一项前瞻性、干预性病例系列研究，源自两家医院的角膜塑形镜临床试验。45 名受试者的双眼均佩戴反转几何设计的镜片，夜间连续佩戴超过 4 小时，持续 52 周。测量未矫正视力、屈光度、眼压（使用非接触眼压计）、中央角膜厚度和角膜曲率。
在接受角膜塑形术之前，未矫正视力、球镜等效值、眼压、中央角膜厚度和角膜曲率半径分别为 0.93±0.27、-2.87±1.05 D、13.5±2.5 mmHg、536.2±39.6 μm 和 7.88±0.25 mm，治疗 52 周后分别为 0.17±0.34、-1.05±1.18 D、12.4±2.7 mmHg、528.6±40.8 μm 和 8.10±0.31 mm。所有参数的变化均有统计学意义，并且眼压的变化与 24 周后 CCT 的变化显著相关。
近视的角膜塑形术会导致非接触眼压计测量的眼压下降，可能是由于 CCT 相关下降所致。
